<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
		<script type="text/javascript">
			//window最顶层对象
			window.onload = function  () {
				var oBox = document.getElementById("box")
				console.log(oBox)
				alert(oBox.innerHTML)
			}
		</script>
	</head>
	<body>
		<div id="box">
			
		</div>
	</body>
</html>
